Next-Generation SAR Amazon Mosaic:
JERS and RADARSAT
Leland
E
Pierce, Univ of Michigan - EECS Dept., lep@umich.edu
(Presenting)
We discuss the development of the next-generation
SAR Amazon mosaic using both L-band JERS and C-band
RADARSAT data.
Rather than using rubber-sheeting-based techniques,
this project uses custom orthorectification programs
to allow for precise positioning, geometric correction,
and radiometric correction made possible by the recent
90-meter-spacing digital elevation model provided by
the Shuttle Radar Topography Mission that flew on the Shuttle
in 2000. This topographic data allows for the correction
of many SAR-related image distortions. We rely on accurate
satellite orbital information as gathered by NORAD and
published on the web to correct for the usually quite
inaccurate orbital information that comes with each image.
Since we are building upon work done by JPL when they processed
the original Amazon mosaic using JERS (L-band) SAR data only,
we are using the same 34 tiles that they used to divide up the
Amazon into manageable pieces.
Each original JERS or RADARSAT image is then orthorectified
onto a tile, and subsequent images are then allowed to
overwrite this same tile until a complete tile is done.
At this point the SAR data is relatively seamless due to the
orthorectification process.
Geometric accuracy will be assessed using natural features
such as rivers and coastlines.
The resulting data will be made available to the public.